This invention relates to a process for production of methacrolein and methacrylic acid by gas phase catalytic oxidation of isobutylene or tertbutanol with molecular oxygen.
Many proposals have been made for catalysts used in production of methacrolein and methacrylic acid by gas phase catalytic oxidation of isobutylene or tert-butanol at high temperatures. However, from an industrial viewpoint, the catalysts used in this reaction have been demanded to be improved in catalytic efficiencies such as catalytic activity, selectivity for methacrolein and methacrylic acid, life of catalyst, etc.
U.S. Pat. No. 4,537,874 discloses MoWBiFe (Ni, Co) alkali metal catalysts, but makes no mention of Cr. Besides, the main feature of the patent resides in subjecting Bi compound and W compound to previous calcination treatment at 600.degree.-900.degree. C. and preparation of catalysts is complicated.